SUSTAINABLE DRYING CABINETSREPLACEMENT PROJECT, UNIVERSITY OF OXFORD

ANDY EVANS - GREEN LIGHT LABORATORIES LTD

INTRODUCTION

Drying cabinets are an essential item of equipment across the chemical and life sciences. However, what was overlooked untilrecently was the design of these units and how much energy they consume.This report will highlight the savings that can be made by replacing the older design drying cabinets with a more energyefficient, modern unit.

THE TRADITIONAL DRYING CABINET

The design of the drying cabinet commonly used over the last 30 years hasn’t really changed. Units tend to consist of a metal box, a hinged or sliding glass door, a heating element and dial to set the temperature from 1 to 10. With zero insulation these units become very hot and consume a lot of energy. The energy consumed by a drying cabinet is remarkably high. In fact ‘pound for pound’ or to be more precise ‘litre for litre’ a drying cabinet at 70C will use up to ten times the energy of an UltraLow Temperature (ULT) freezer set at -80C! The University of Oxford had 159 of traditional unit types.

Figure 1. The traditional design of drying cabinet.

REPLACING OLD WITH NEW

The University of Oxford carried out the largest drying cabinet replacement project in the UK. The traditional type units werereplaced with the next generation of drying cabinets. The differences between these two model types are shown in figure 2.

5-OCT-18

Figure 2. Old drying cabinet design features versus the new E3 models.

The 159 traditional units were replaced with 154 E3 models.The improvements in energy efficiency and programming the replacement units to operate from 7am to 7pm Monday resulted in a 72% reduction in energy consumption (figure 3).

SUSTAINABLE DRYING CABINETSREPLACEMENT PROJECT, UNIVERSITY OF OXFORD

ANDY EVANS - GREEN LIGHT LABORATORIES LTD

5-OCT-18

The 72% reduction in energy consumption is a conservative figure as a number of the older units were being used at a 50Cset point and their energy consumption has been compared to all E3 models running at 75C. Furthermore the savings calculated

do not include any associated savings in air conditioning gained form the reduced heat output into the laboratory.The replacement E3 models (figure 4) have an estimated lifespan of 15 years.

This would mean that for the remaining 10+ years of their lifespan the University will save in excess of £500,000 in electricity costs and 1,400 tonnes of carbon emissions.

AKNOWLEDGEMENTSSpecial thanks to all those who made this study possible in particular:Mr. Tom Heel and Miss Stefanie Reiss, Environmental Sustainability, University of Oxford

For further information on this study, or lab sustainability in general please contact Andy Evans, office@greenlightlabs.co.uk. 07833 4947275-Oct-18 Sustainable Drying Cabinets 1

Figure 3. Project savings (£0.10/kWh, 283g/CO2e/kWh)

Figure 4. 200L E3 drying cabinet.